Fix lmtp_save_to_detail_mailbox to be case insensitive?

[dovecot at ptld.com]

To bring this up again because i have not found a work around solution.
Can dovecot make lmtp_save_to_detail_mailbox case-insensitive?

If you create a folder "foobar" then an email with recipient user+foobar at example.com will be placed in the folder.

However with the folder as "foobar" an email with recipient user+FOOBAR at example.com will report folder "FOOBAR" not found and the email will be placed in the inbox folder.